The present invention relates to the field of laser printing device process (toner) cartridge remanufacture in which a reassembled toner cartridge is resealed by ultrasonic welding.
Process or toner cartridges for laser printing are engineered and manufactured to a high degree of precision necessary for proper operation and good printed image quality. Central to proper operation of a process (toner) cartridge is proper alignment and orientation of its various components, as well as proper sealing of the cartridge to avoid the leakage of toner. Original equipment manufacturers achieve the rigidity necessary to maintain the alignment and orientation of components, in substantial part, by ultrasonically welding the sections of the toner or process cartridge together. The process of remanufacturing a toner or process cartridge requires that the cartridge be disassembled and that a hopper section of the cartridge which holds the toner be separated from a roller section which contains the developer roller and other components. When the hopper and roller sections are separated, however, alignment and orientation of components B including particularly that between the developer roller and sealing bladexe2x80x94as well as between other rollers and blades may be lost.
Heretofore, a problem has existed in aligning the various components including, including the sealing blade and/or the developing blade with the developer roller with the necessary precision during reassembly of the sections of the process or toner cartridge. A conventional approach to this problem has been to manually align and fit the sections of the cartridge together, with or without the aid of a positioning jig, then manually to secure the sections together with a number of clips or with adhesive or glue. These techniques, while generally effective suffer a number of drawbacks.
One such drawback is that both clips and adhesive are consumables which increase production costs and cost of the final product. Another drawback is that manual reassembly is quite labor intensive and is subject to human error and variation in quality. In the case of reassembly with adhesive or glue, there typically is a period of a few to several minutes for bonding to take place during which alignment must be maintained, which increases production time and cost. Further, resealing with adhesive often fuses or bonds the sections together, rendering subsequent separation for additional remanufacturing cycles more difficult.
An additional drawback in the use of clips to reassemble the process or toner cartridge is that the rigidity imparted by the original ultrasonic weld is difficult to achieve, and over the life of the cartridge the clips may loosen or become disengaged entirely. In such event, as a result of loss of proper positioning the various components of the cartridge may no longer function as intended. For example, improper positioning of the sealing blade and/or developing blade with the developer roller, may permit excessive toner to accumulate on the developer roller with the result that a mass of excess toner will be transferred to the photoconductive printing drum and thence to the printer paper thereby degrading the printed image quality. Further, disengagement or loosening of a clip may permit toner to leak from the cartridge. In many laser printing devices (such as printers, facsimile machines or copiers), the path of the paper through the printing device passes nearby to the process (toner) cartridge where the clips have been installed. Hence, papers jams may occur if a loose clip projects into the paper path.
Plastic process or toner cartridges manufactured from new components by original equipment manufactures typically are sealed by ultrasonic welding, a technique that until now has been unavailable for use in the remanufacture or reassembly of process or toner cartridges. An impediment to the use of ultrasonic welding in rejoining the sections of a process (toner) cartridge during remanufacture and reassembly is that the ultrasonic energy director element is largely consumed or obliterated by the ultrasonic welding process in the course of original manufacture of the cartridge. Typically, an ultrasonic energy director element is a relatively small featurexe2x80x94usually in the form of a ridge or bumpxe2x80x94which extends slightly above the surface of the surrounding area and which contacts a juxtaposed surface to be joined. The energy director is of the same material as the plastic component and is formed in the mold in which the plastic component was originally created. During the ultrasonic welding process it is the energy director element which first melts as a result of frictional heating created by the ultrasonic frequency vibrations between the two surfaces to be welded. It is the melting together of the surfaces, at the location of the energy director element, which upon cooling and solidification, welds the two surfaces together. Thus, the energy director element is melted and largely consumed or obliterated in welding together the sections of the cartridge in the original manufacture of a new process or toner cartridge. Hence, upon separation of the cartridge sections by cutting along the original ultrasonic weld during the remanufacturing process, there no longer exists a complete energy director element from which to initiate ultrasonic welding of these components.
The present invention provides a remanufactured process or toner cartridge and method of manufacture in which the sections of the cartridge are ultrasonically welded together without replacing the energy director elements, and without use of consumable components.
In its several embodiments, the present invention provides an operational laser printer device process (toner) cartridge which has been remanufactured and reassembled from components including those from previously depleted toner cartridges, and further provides a method whereby this may be accomplished.